In the aforementioned co-pending application, a conversion apparatus and method is disclosed wherein radiant energy is converted into electric energy with a pyroelectric device including an ionic dielectric of the type having a dipole layer only on or near its surface in proximity to an electrode. In the prior art device, the dielectric is a single crystal formed from the group consisting of the rare earth trifluorides and trichlorides; lanthanum trifluoride is the preferred compound forming the dielectric. Being pyroelectric, the single crystal devices of the prior art are heated by the impinging radiant energy, without undergoing any Curie point phase transition. In response to the dielectric being heated, the capacitance and resistance of the dielectric are varied. Preferably, the dielectric is periodically irradiated, resulting in cyclic variations of the dielectric capacitance and resistance. It was originally thought that the class of materials utilized in the prior art device would function only by heating from the radiant energy.